KUHL tube treatment - is this black smoke????


So i was told that Kuhl treatment of a tube and for me a 396a JW 2c51 tube.. would be a worthy enhancement ...

What do you guys think?

{ quoted from TUBEWORLD ]

In stock form, a typical electron tube exhibits several problems that directly impact its sonic performance. Most serious are the many internal stresses in the construction materials that accumulate during most of the stages of manufacture and a very hard, heavy oxide-coating on through-glass pins to which direct connection is made. Seven (7) and nine (9) pin miniature tubes are typical of those pins that are heavily oxidized while power tubes such as KT88 and EL34 are fitted with bases whose pins are tinned with the result that contact quality is much improved. During cryogenic tempering, the tube is slowly cooled to the -193°C / -320°F temperature of liquid nitrogen (LN2), "soaked" for 36 hours, then slowly returned to ambient temperature.

By means of this unique and vital process, the stresses interior to the materials of the tube are substantially and permanently relaxed. The "Q" of the (self) resonant (electro) mechanical systems responsible for the output of (self) microphonic spuriae is thereby drastically reduced. By this important reduction, both the peak amplitude and the "ring down" time of these systems is reduced with the result that the "apparent gain" of the tube is increased - even in feedback controlled circuits - while the "dynamic noise floor" is lowered.

The sonic improvements of a over a "factory condition" NOS tube include:

tighter focus from top to bottom
more holographic 3D soundstage
more subtle inner resolution extracted from recordings
tighter bass
increased dynamic range
faster transient response
clearer vocals
davidtemple
Many complaints about premature failures on cryoed tubes. Extremely low temperatures may be stressing internal parts.
Rrog wrote,

"Many complaints about premature failures on cryoed tubes. Extremely low temperatures may be stressing internal parts."

Yeah, right.
Rrog, what source are the complaints from ? I have not heard of such complaints.

My opinion is the tubes should be ran through several tests prior to cryogenic treatment. A poorly constructed tube will fail whether it is cryoed or not. A microphonic tube will still be microphonic, possibly slightly less.

I've sent a few things in for cryogenic treatment. The slight improvement is sometimes not worth the hassle and expense. The best bet, as many cable makers do, is treat the conductors first before making the cable. This seems like a real hassle to me, because how are you going to get the insulation back on ?

Another thing is any moisture in the air of the cryogenic chamber, will condense, making things wet, then the liquid on the parts will freeze. I believe this is why some parts look "old" after treatment. So the chamber should be de-humidified before taking the temperature down (or more correctly, removing the heat).
This would apply only on the outside of a vacuum tube.

So my advise is; if you really want to try it, start with some good sounding tubes, and preferably have an extra set to compare to (see how expensive this gets?). And if you buy them already cryoed, make sure there is a return period. Try them right away and make sure there is nothing at all wrong with the tubes; no funny noises, no ringing, etc.
Best of luck to you.